2 files changed, 23 insertions, 4 deletions

diff --git a/Help/prop_sf/Fortran_FORMAT.rst b/Help/prop_sf/Fortran_FORMAT.rst
index 1cbbf48..ef33926 100644
--- a/Help/prop_sf/Fortran_FORMAT.rst
+++ b/Help/prop_sf/Fortran_FORMAT.rst
@@ -4,7 +4,9 @@ Fortran_FORMAT
 Set to ``FIXED`` or ``FREE`` to indicate the Fortran source layout.
 
 This property tells CMake whether a given Fortran source file uses
-fixed-format or free-format.  CMake will pass the corresponding format
-flag to the compiler.  Consider using the target-wide
-:prop_tgt:`Fortran_FORMAT` property if all source files in a target
-share the same format.
+fixed-format or free-format.  CMake will pass the corresponding format flag
+to the compiler.  Consider using the target-wide :prop_tgt:`Fortran_FORMAT`
+property if all source files in a target share the same format.
+
+.. note:: For some compilers, ``NAG``, ``PGI`` and ``Solaris Studio``,
+          setting this to ``OFF`` will have no effect.
diff --git a/Help/prop_sf/Fortran_PREPROCESS.rst b/Help/prop_sf/Fortran_PREPROCESS.rst
new file mode 100644
index 0000000..25ea827
--- /dev/null
+++ b/Help/prop_sf/Fortran_PREPROCESS.rst
@@ -0,0 +1,17 @@
+Fortran_PREPROCESS
+------------------
+
+Control whether the Fortran source file should be unconditionally preprocessed.
+
+If unset or empty, rely on the compiler to determine whether the file
+should be preprocessed. If explicitly set to ``OFF`` then the file
+does not need to be preprocessed. If explicitly set to ``ON``, then
+the file does need to be preprocessed as part of the compilation step.
+
+When using the :generator:`Ninja` generator, all source files are
+first preprocessed in order to generate module dependency
+information. Setting this property to ``OFF`` will make ``Ninja``
+skip this step.
+
+Consider using the target-wide :prop_tgt:`Fortran_PREPROCESS` property
+if all source files in a target need to be preprocessed.